The present invention relates to novel piperidinone compounds, which are formyl peptide 2 (FPR2) receptor agonists and/or formyl peptide 1 (FPR1) receptor agonists, compositions containing them, and methods of using them, for example, for the treatment of atherosclerosis, heart failure, chronic obstructive pulmonary disease (COPD), and related diseases.
Formyl peptide receptor 2 (FPR2) belongs to a small group of seven-transmembrane domain, G protein-coupled receptors that are expressed mainly by mammalian phagocytic leukocytes and are known to be important in host defense and inflammation. FPR2 shares significant sequence homology with FPR1 and FPR3. Collectively, these receptors bind a number of structurally diverse agonists, including N-formyl and nonformyl peptides which act as chemo attractants and activate phagocytes. The endogenous peptide Annexin A1 and its N-terminal fragments also bind human FPR1 and FPR2. Importantly, eicosanoid lipoxin A4, which belongs to a class of small pro-resolution mediators (SPMs), has been identified as a specific agonist for FPR2 (Ye R D., et al., Pharmacol. Rev., 2009, 61, 119-61).
Endogenous FPR2 pro-resolution ligands, such as lipoxin A4 and Annexin A1 bind to the receptor triggering a wide array of cytoplasmatic cascades such as Gi coupling, Ca2+ mobilization and β-arrestin recruitment. Activation of FPR2 by lipoxin A4 modifies the effects of peptidic agonists, such as serum amyloid A (SAA), and has alternative effects on phosphorylation pathways depending on the cell type. Lipoxins regulate components of both innate and adaptive immune systems including neutrophils, macrophages, T-, and B-cells. In neutrophils, lipoxins modulate movement, cytotoxicity and life span. In macrophages, lipoxins prevent apoptosis and enhance efferocytosis. In most inflammatory cells, lipoxins also down-regulate expression of several pro-inflammatory cytokines, such as IL-6, IL-1β and IL-8 as well as up-regulate expression of anti-inflammatory cytokine IL-10 (Chandrasekharan J A, Sharma-Walia N., J. Inflamm. Res., 2015, 8, 181-92). The primary effects of lipoxin on neutrophils and macrophages are termination of inflammation and initiation of resolution of inflammation. The latter is primarily responsible for enhancing anti-fibrotic wound healing and returning of the injured tissue to homeostasis (Romano M., et al., Eur. J. Pharmacol., 2015, 5, 49-63).
Chronic inflammation is part of the pathway of pathogenesis of many human diseases and stimulation of resolution pathways with FPR2 agonists may have both protective and reparative effects. Ischaemia-reperfusion (I/R) injury is a common feature of several diseases associated with high morbidity and mortality, such as myocardial infarction and stroke. Non-productive wound healing associated with cardiomyocyte death and pathological remodeling resulting from ischemia-reperfusion injury leads to scar formation, fibrosis, and progressive loss of heart function. FPR2 modulation is proposed to enhance myocardial wound healing post injury and diminish adverse myocardial remodeling (Kain V., et al., J. Mol. Cell. Cardiol., 2015, 84, 24-35). In addition, FPR2 pro-resolution agonists, in the central nervous system, may be useful therapeutics for the treatment of a variety of clinical I/R conditions, including stroke in brain (Gavins F N., Trends Pharmacol. Sci., 2010, 31, 266-76) and I/R induced spinal cord injury (Liu Z Q., et al., Int. J. Clin. Exp. Med., 2015, 8, 12826-33).
In addition to beneficial effects of targeting the FPR2 receptor with novel pro-resolution agonists for treatment of I/R induced injury therapeutic, utility of these ligands can also be applied to other diseases. In the cardiovascular system both the FPR2 receptor and its pro-resolution agonists were found to be responsible for atherogenic-plaque stabilization and healing (Petri M H., et al., Cardiovasc. Res., 2015, 105, 65-74; and Fredman G., et al., Sci. Trans. Med., 2015, 7(275); 275ra20). FPR2 agonists also have been shown to be beneficial in preclinical models of chronic inflammatory human diseases, including: infectious diseases, psoriasis, dermatitis, occular inflammation, sepsis, pain, metabolic/diabetes diseases, cancer, COPD, asthma and allergic diseases, cystic fibrosis, acute lung injury and fibrosis, rheumatoid arthritis and other joint diseases, Alzheimer's disease, kidney fibrosis, and organ transplantation (Romano M., et al., Eur. J. Pharmacol., 2015, 5, 49-63, Perrett, M., et al., Trends in Pharm. Sci., 2015, 36, 737-755).